Heart rhythm disorders (arrhythmias) occur when there is a malfunction in the electrical impulses to the heart that coordinate how the heart beats. During arrhythmia, a heart may beat too fast, too slowly or irregularly. Catheter ablation is a widely used therapy for treating arrhythmias and involves threading a catheter through blood vessels of a patient and into the heart. In some embodiments, radio frequency (RF) energy may be applied through the catheter tip to destroy abnormal heart tissue causing the arrhythmia. In other embodiments a catheter tip may be configured to cryogenically ablate heart tissue.
Guiding the placement of a catheter during ablation therapy within the heart is important. Conventional catheter ablation procedures are conducted using X-ray and/or ultrasound imaging technology to facilitate catheter guidance and ablation of heart tissue. Conventional Cardiac EP (ElectroPhysiology) Systems are X-ray based systems which use electroanatomical maps. Electroanatomical maps are virtual representations of the heart showing sensed electrical activity. Examples of such systems include the Carto® electroanatomic mapping system from Biosense Webster, Inc., Diamond Bar, Calif., and the EnSite NavX® system from Endocardial Solutions Inc., St. Paul, Minn.
However, there remains a need for MRI-guided systems that can use MRI to obtain details of tissue not provided by X-ray based systems and/or to reduce patient exposure to radiation associated with interventional (diagnostic and/or therapeutic) procedures.